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Publication numberUS4862160 A
Publication typeGrant
Application numberUS 07/028,342
Publication date29 Aug 1989
Filing date20 Mar 1987
Priority date29 Dec 1983
Fee statusLapsed
Publication number028342, 07028342, US 4862160 A, US 4862160A, US-A-4862160, US4862160 A, US4862160A
InventorsJack A. Ekchian, Robert W. Hoffman, Leon Ekchian, Kaigham J. Gabriel
Original AssigneeRevlon, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Item identification tag for rapid inventory data acquisition system
US 4862160 A
Abstract
A computerized transceiver repeatedly sweeps through a set of transmit/receive frequencies to interrogate collectively a plurality of groups of items in a stocking area. Items in each group are tagged with a printed circuit transponder tuned to frequencies uniquely assigned to each group. Data returned is stored and combined mathematically by the computer to arrive at the total number of items in each group. The system is particularly adapted for taking inventory of a large number of retail shelf goods using a mobile transceiver.
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Claims(4)
What is claimed is:
1. A method of forming electronically differentiatable item tags for plural groups of items, comprising the steps of
supplying a plurality of tags, each comprising at least two electronic circuit elements with adjustable electronic properties determined by the length of said elements, said circuit elements being a pair of coaxial, coplanar, interleaved, spiral conductive arms,
assigning a unique set of said electronic properties to each group of items,
dividing the tags up into sets corresponding to respective groups of items,
adjusting the circuit elements of the tags in each set to achieve the electronic properties assigned to the corresponding group, the step of adjusting to achieve electronic properties including altering the length of said arms, and
affixing the tags in each set to the items in the corresponding group,
whereby collectively testing the tags on an arbitrary number of items ascertains the membership of said groups.
2. A method of forming electronically differentiatable item tags for plural groups of items, comprising the steps of
supplying a plurality of tags, each comprising at least two electronic circuit elements with adjustable electronic properties determined by the length of said elements, said circuit elements including a plurality of coaxial, coplanar, interleaved, spiral conductive arms arranged in adjacent pairs of differing lengths corresponding to specified different frequencies,
assigning a unique set of said electronic properties to each group of items,
dividing the tags up into sets corresponding to respective groups of items,
adjusting the circuit elements of the tags in each set to achieve the electronic properties assigned to the corresponding group, said step of adjusting including altering the lengths of plural pairs of said arms, and
affixing the tags in each set to the items in the corresponding group,
whereby collectively testing the tags on an arbitrary number of items ascertains the membership of said groups.
3. The method of claim 2, wherein said arms consist of three pairs of juxtaposed arms, two of the pairs corresponding to a remotely transmitted pair of frequencies, the third pair of arms corresponding to a third frequency which is an algebraic function of the pair of transmitted frequencies.
4. The method of claim 3, wherein said step of assigning a unique set of electronic properties includes determining a unique set of said three frequencies, said step of adjusting including altering the lengths of the arms in each of said three pairs to correspond to said unique set of three frequencies.
Description

This is a division of application Ser. No. 566,534, filed Dec. 29, 1983 U.S. Pat. No. 4,673,932.

BACKGROUND OF THE INVENTION

The present invention relates generally to inventory control and more particularly to automatic shelf inventory data systems.

The availability of inventory technology coupled with the sales downturn and increased operating costs of recent recessionary periods have combined to force retailers to meet competitors' aggressive pricing by using more stringent inventory control techniques. The hidden costs associated with excess inventory or overstocking in the competitive retail industry are critically important. Large retailers estimate that the true cost of carrying inventory is on the order of 40% of the cost of the item per year. Moreover, the more inventory, the more manpower is required for inventory control. Most importantly to the retail food and drug trade, however, overstocking results in inflexible pricing. In many stores, electronic cash registers at the checkout counters have been replaced by computerized point of sale terminals. Optical scanners and bar codes on products, while posing other problems, allow flexible pricing and computerized real time inventory control and automated stock ordering. All in all, the various types of material requirement planning systems available today throughout the retail, wholesale and manufacturing sectors have become a indispensable tool of cost control.

Establishing precise control over retail inventory, however, requires more than reading bar codes at the checkout counter. In order to be purchased, products have to not only be ordered but delivered, uncrated, unboxed, marked and moved from the stock room onto the shelves or peg racks in the retail store. Even overstocked items will fail to reach the checkout counter unless they are on the shelf.

Taking inventory for reordering or restocking of shelves is time consuming but essential, particularly where individual stores such as discount drug stores, stock thousands of shelf items. Shelf stock-taking should be fast and inexpensive to encourage daily adjustments. However, today shelf inventory taken by visual inspection often requires manipulation of individual products hung eight deep on a peg rack. Bar codes are of little use on the shelf since they are usually hidden from view and in any event must be individually scanned. Ironically, the optical techniques which are so efficient at the checkout counter are ill adapted for inventorying shelf goods.

SUMMARY OF THE INVENTION

Accordingly, the general purpose of the invention is to automatically inventory shelf goods without individual scanning or manipulation.

A corollary object of the invention is to produce an inventory of individual products by stock keeping unit (SKU) by collectively, remotely and automatically ascertaining the quantity of products for a series of SKU's comingled on a given shopping aisle.

These and other objects of the invention are achieved by tagging each product with a tiny passive resonant transponder, preferably in the form of a printed circuit small enough to be attached unobtrusively to a lipstick, and employing a computerized transceiver, preferably mounted on a wheeled cart, to repeatedly sweep through a set of transmit/receive frequencies to interrogate collectively all the products belonging to specific SKU's arranged on a peg rack, for example. The data returned during interrogation at each SKU-specific frequency set is stored and combined mathematically by the computer to arrive at the total number of products in each of the interrogated SKU's for a given stocking area in a drug store or supermarket, for example.

In the preferred embodiment, the mobile transceiver transmits at a pair of frequencies specific to a given SKU. Products of that SKU are equipped with tags which resonate at the unique pair of frequencies and reradiate simultaneously a third frequency to which the receiver portion of the transceiver is tuned. The amplitude of the third frequency detected by the receiver is a function of distance, receiver antenna pattern and the number of tag products present on the shelf or peg rack of the particular SKU. As the transceiver moves down the aisle, the transceiver, preferably under software control, sweeps through the plurality of SKU specific transmit/receive frequency sets.

In the preferred embodiment, the frequencies are derived from a master crystal oscillator and tuned in phase-locked loop frequency synthesizing circuits so that they will track precisely the nominal SKU frequency sets.

The preferred form of the tag itself is a circular printed circuit having three sets of two interleaved, coaxial, sprial conductive arms providing three tuned circuits. Each pair of arms can be cut to length corresponding to a frequency. The arm pairs are nonlinearly, mutually capacitively and inductively coupled so that upon excitation at transmit frequencies, the tage emits a third frequency which is a function (preferably the sum) of the first two frequencies.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a pictorial perspective view of the transceiver cart in a shopping aisle according to the invention.

FIG. 2 is a schematic representation of the transceiver interrogating a tagged product according to the invention.

FIG. 3 is a plan view of a printed circuit tag according to the invention.

FIG. 4 is an electrical schematic drawing representing an idealized equivalent circuit for the tag of FIG. 3.

FIG. 5 is a block diagram of the transceiver according to the invention.

FIG. 6 is a block diagram of one of the phase-locked loops of the transceiver of FIG. 5.

FIG. 7 is a block diagram of an alternate embodiment of a portion of the transmitter circuitry.

FIG. 8 is a block diagram of an alternate embodiment of a portion of the receiver circuitry.

FIG. 9 is a schematic representation of a retail pegboard rack from the front displaying products of a specific SKU as dots.

FIG. 10 is a histogram representing the quantity of products in each incremental unit of distance along the peg rack.

FIG. 11 is a graph showing the radiated signal pattern as a function of displacement along the peg rack.

FIG. 12 is a three-dimensional graph of the radiated signal pattern as a function of displacement along the peg rack and the product's elevation above the floor.

FIG. 13 is a graph of the received energy from plural tags as a function of displacement along the peg rack.

DETAILED DESCRIPTION

As shown in FIG. 1, the interrogation system is mounted on a cart 10 which can be wheeled down an aisle in a retail store alongside a pegboard type display rack 12 bearing products which are to be inventoried. As shown in FIG. 2, the transceiver 14 under the control of the microcomputer 16 transmits a pair of frequencies F1 and F2 corresponding to a given SKU. A packaged product 20 of the SKU being interrogated is equipped with a specially designed printed circuit tag 22 which is resonant at the transmitted frequencies and simultaneously reradiates a third frequency signal F3 which is picked up by the antenna 18 and received in the transceiver 14. The strength of the return at F3 is measued and stored as the cart 10 rolls along the display rack 12 and the stored data is processed by an on-board programmed microcomputer 16 to produce a numerical display 24 of the total number of units in the given SKU corresponding to the frequency set F1, F2, and F3. As the cart is wheeled down the aisle, the microprocessor controls the transmitter in the transceiver 14 to sweep stepwise through all of the pertinent SKU's entered via the keyboard 26 (FIG. 1). The resulting numerical quantities of products in each designated SKU are printed out on command at the end of the aisle or when the shelf inventory for the entire store is completed. As an aid in processing the return signal strength, the cart 10 is equipped with an odometer 30 which keeps track of displacement in the X direction along the length of the peg rack and a sonar ranging device 32 for keeping track of the distance of the cart 10 from the peg rack 12.

As shown in FIG. 3, each product tag 22 comprises six coaxial interleaved conductive arms 34, 36, 38, 40, 42 and 44 mounted on a flexible nonconductive substrate 46. The arms themselves are made of etched copper foil in the manner of a printed circuit. The inner ends of the arms are connected to an array of six spaced terminals, while the outer ends are trimmed to length. The interwoven spiral arms are paired in such a manner that there is a pair corresponding to F1, another pair corresponding to F2, and a third pair corresponding to F3. Each pair is tuned to the corresponding frequency by trimming the length of the corresponding arms. The respective pairs are nonlinearly mutually capacitively and inductively coupled so that upon excitation at frequencies F1 and F2, the tag emits a third frequency F3 which is the sum of the frequencies of F1 and F2. By assigning uniquely cut tags to each SKU, all of the products on the shelf can be differentiated by their frequency response. The nonlinear capacitance effect is equivalent to a mild piezoelectric effect and is designed to be essentially nondirectional so that the response will be independent of the products attitudue or orientation on the shelf. The tag is intended in the preferred embodiment to be about the size of a fingernail, approximately 1/4 to 3/8 of an inch in diameter and can be concealed in the packaging itself since it is unnecessary to optically scan the tag. Moreover, the tag can be bent or wrapped, e.g., around a lipstick, without noticeable effect on the function.

The equivalent circuit shown in FIG. 4 illustrates the nonlinear mutual coupling capacitors between the spiral arms. The needed capacitance provided through the proximity of the antenna elements in the tag can be enhanced by the use of a solid sheet conductor on the other side of the nonconductive substrate 46. The coaxial resonator tag system is a completely passive transponder in the sense that the only energy which it consumes is that which it receives from the transmitter on the cart.

The transceiver 14 consists of three major portions: the transmitter, receiver and the microcomputer 16 which controls the system. In the transmitter, two precise frequencies are generated under computer command by phase-locked frequency synthesis. The two frequencies are radiated to the SKU-specific tags which act as radio frequency resonantors and transponders. A particular tag will reradiate a frequency equal to the sum of the transmitted frequencies if the transmitted frequencies are the particular ones that the tag is tuned to. If the tag is not tuned to the transmitted frequencies, it will not return a signal. The receiver section is instructed by the microcomputer to "listen" for the sum frequency corresponding to the two transmitted frequencies. The receiver is tuned by means of another phase-locked synthesizer. The computer sequences the synthesizers through each selected set of frequencies.

In the transceiver circuit of FIG. 5, the 1 MHz output of a crystal oscillator 50 is divided by 200 in counter circuit 52. The resulting 5 KHz reference signal is fed in parallel to three phase-locked loops 54, 56 and 58 corresponding to frequencies F1, F2 and F3, respectively. Each phase-locked loop is implemented as shown in FIG. 6. The 5 KHz reference signal forms one input to a phase comparator 60 whose output is fed via a charge pump 62, phase compensation circuit 64 and amplifier 66 to the conytrol input of a voltage controlled oscillator 68. The output of the oscillator 68 is a continuous wave signal which is fed via the power amplifier 70 to coaxial output cable 72. The output of the voltage controlled oscillator 68 also forms the input to a feedback loop comprising buffer amplifier 74, a frequency halving circuit 76 and a divide by N circuit 78. The divided down output of the phase-locked loop circuit forms the other input to the phase comparator 60. The value of N is determined by the microcomputer via a suitable interface chip 80 in order to select the specific value for frequency F1, F2 or F3 associated with each SKU.

As shown in FIG. 5, the output of two of the phase-locked loops are in nonoverlapping respective ranges 20-24 MHz and 25-29 MHz. These outputs are combined in a summation circuit 82 and amplitude modulated in modulator 84 by a 1,000 Hz square wave derived from the 5 KHz reference signal via divider circuit 86. The amplitude modulated sum of signals F1 and F2 is fed via RF amplifier 87 and diplexer circuit 88 to antenna 18. The other side of the diplexer 88 feeds the received signal via another RF amplifier 89 through a 43-53 MHz bandpass filter 90 to a first mixer 92 which sums the received signal minus higher and lower frequency noise with the unmodulated F3 output of phase-lock loop circuit 58 which serves as a local oscillator. Mixer 92 produces a 10.7 MHz output signal which is amplified in IF amplifier 94 and passed to a second mixer 96 which mixes the first IF output with the output of a 10.245 MHz crystal oscillator 98. The output of mixer 96 is fed via a 455 KHz IF amplifier 100 to a synchronous demodulator 102 which demodulates the received signal with the benefit of the 1,000 Hz modulation signal. The demodulated received signal is fed via analog-to-digital converter 104 (preferably 12-bit) back to the microcomputer 16 for processing.

A variation on the transmit circuit of FIG. 5 is shown in FIG. 7 in which the frequencies F1 and F2 are kept entirely separate. In experiments with a circuit constructed according to FIG. 5, it was discovered that third order intermodulation distortion of the output amplifier was high enough that simple filtering left the harmonic sum of F1 and F2 at a higher strength than the received reradiated signal from the tags. This problem is addressed in FIG. 7 by providing separate modulators 110 and 112, RF amplifiers 114 and 116, filters 18 and 120 and separate transmit antennas 122 and 124. Filters 118 and 120 should be carefully designed to eliminate mixing of the other frequency at the output of either amplifier 114 or 116.

An alternate design for a portion of the receiver is shown in FIG. 8. A separate receive antenna 126 is used and after RF amplifier 89, the bandpass filter 90 is replaced by an varactor-tuned dual helical filter 128 which is controlled by the microcomputer via a digital-to-analog converter 130. The filter 128 can be approximately tuned to the desired received frequency to exclude unwanted interference.

Antennas used in the designs of FIGS. 5, 7 and 8 are center-loaded, short, vertical dipole whip antennas. Common practice is to make such antennas one-quarter wave length in length. However, at 30 MHz, this results in an impractically long antenna. Thus, the efficiency of the antenna is sacrificed to reduce its length. At higher frequencies more suitable for use with the tag design of FIG. 3, a more efficient antenna design will become practical. The vertical whip-type antenna, which exhibits linear polarization may be effectively replaced by a circular-polarized design to minimize variations in signal strength due to tag orientation.

With reference to FIG. 9, assume that the pegboard rack has a number of products of the same SKU distributed as indicated by the dots. Displacement of the interrogation cart 10 (FIG. 1) in the X direction is indicated by the arrow marked X.

The histogram in FIG. 10 represents the exact quantity of products in any incremental slot delta X. This function is designated V(x) where V represents the specific number of products at any given location along the x axis. A single radiating tag, for example, tag 22 in FIG. 9 produces a radiated field with an intensity which exhibits an exponential distribution over the x axis as shown in the graph of FIG. 11, H(x) representing the signal strength. Signal strength is also, of course, a function of displacement in the vertical direction from the radiating tag 22, however, as shown in the graph of FIG. 12, the slight variation can be safely ignored in most instances.

If the cart 10 were rolled along direction x from right to left in FIG. 9, transmitting at the combination of frequencies F1 and F2 uniquely assigned to this particular SKU identified by the dots, the strength of the received signal would be distributed over the x axis as shown in the graph of E(x) in FIG. 13.

Due to the overlap produced by the finite width of the radiated signals, the waveform in FIG. 13 does not duplicate the histogram of FIG. 10. Since the desired quantity, the inventory, consists of a sum and does not require reconstructing the exact shape of the waveform as received, the microcomputer 16 is programmed to perform a numerical integration of the area under the curve of the graph of FIG. 13.

Assume that E(delta xi) is proportional to m, where m is the total number of products in the ith delth x slot. E, a function of x, is generally the convolution of the distribution function V(x) convolved with the radiated signal pattern function H(x) as given by the Equation 1.

E(x)=V(x)*H(x)                                             (1)

Applying Fourier transforms to equation 1 results in Equation 2,

ε(ν)=V(ν)H(ν)                             (2)

which, when solved for the actual distribution function as a function of the frequency ν, results in the following equation (Equation 3). ##EQU1## Thus, the actual distribution function is a ratio between the reconstructed pattern as measured and the transformed radiated signal pattern. The total number of products on the shelf T is (Equation 4).

t=∫V(x)dx                                             (4)

Equation 4 can also be represented as the Fourier transform of the distribution function evaluated where frequency equals 0.

T=V(ν)|.sub.ν=0                             (5)

Substituting the ratio of Equation 3 and replacing the Fourier transformed ratios with plain integrals of the untransformed distribution functions results in Equation 6. ##EQU2## Since a complete reconstruction of the distribution pattern is unnecesary as only the total number of products is desired, the Fourier transforms may be replaced by a simple running integral of the observed waveforms. ##EQU3##

Thus, the ratio shown in Equation 7 is sufficient to produce the total number of products on the shelf as measured during a walk-down of the shelf. Hence, a simple numerical integration can be performed on the received data by the microcomputer 16 contained in the transceiver unit to produce the readout shown in FIG. 2 of the quantity of a particular SKU on the shelf.

The numerator of Equation 7 is a running numerical integration; the denominator is a measured system constant related to the signal pattern radiated by each tag. The running integration is best performed by a separate mathematical processor such as the Intel 8087 used as a coprocessor in conjunction with a main controller microprocessor such as the Intel 8086.

Since each product responds to a unique combination of frequencies F1 and F2, the microprocessor must be fast enough to sweep through all possible combinations so that for a given minimum interproduct spacing delta x, each such delta x is sampled at least once for each SKU specific frequency set. The response at F3 is processed by numerical integration providing a running sum for each product on the rack.

The advantages of the above described automatic shelf inventory system are be readily apparent. Radio frequency interrogation of comingled tagged products on a rack eliminates hand counting, visual inspection of thousands of SKU's in a given retail store. The ability to establish precise control over the shelf inventory assures optimized inventory flow from the stockroom to the checkout counter. The retailer's profits are increased by eliminating inadvertant stock-out conditions. Moreover, the system is so fast and potentially inexpensive that it can be used on a daily basis to track shelf inventory trends and make adjustments to inventory.

The unique tag of the present invention can be mass-produced by printed circuit techniques and can be made small enough to be invisibly incorporated in the packaging of even the smallest shelf items. The novel mobile interrogator enables an unskilled operator to completely inventory the shelf stock in a retail store without counting a single SKU. Thus, human error is eliminated. The appropriate SKU numbers can be entered for a given aisle by preloading the computer memory with the SKU's which are normally stocked on a particular rack. Thus, the operator would only have to enter the rack number. Alternatively, given sufficient computer speed and settling time for the transceiver, all of the store's SKU's could be interrogated on each walk-down of each rack. Because the frequencies are all derived from a single master crystal oscillator, any drift would be experienced on all three frequencies simultaneously and the effect will be minimized.

The foregoing description of the presently preferred embodiments is intended to be illustrative and not restrictive. Many variations and modifications of the overall system or individual components are possible, still employing the underlying principle of the invention, without departing from the scope of the invention as indicated by the appended claims and equivalents thereto.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3246245 *5 Jun 196112 Apr 1966Turner Edwin MCombined antenna and converter circuit
US3671721 *12 Dec 196920 Jun 1972Revenue Systems LtdData reading systems
US3707711 *2 Apr 197026 Dec 1972Peter Harold ColeElectronic surveillance system
US3714566 *2 Sep 197030 Jan 1973Bunker RamoApparatus and methods for deriving in essentially real time continuous electrical representations of the fourier and inverse fourier transform
US3731273 *26 Nov 19711 May 1973W HuntPosition locating systems
US3752960 *27 Dec 197114 Aug 1973C WaltonElectronic identification & recognition system
US3780368 *19 Feb 197118 Dec 1973SvejsecentralenMethod of marking and subsequently localizing, identifying and recording physical objects
US3816708 *25 May 197311 Jun 1974Proximity DevicesElectronic recognition and identification system
US3842246 *27 Sep 197315 Oct 1974Proximity DevicesRecognition and identification system with noise rejection capabilities
US3969732 *24 Apr 197513 Jul 1976Holloway Albert LSpiral antenna circuit
US4021705 *24 Mar 19753 May 1977Lichtblau G JResonant tag circuits having one or more fusible links
US4087821 *14 Jul 19762 May 1978Harris CorporationPolarization controllable lens
US4160971 *29 Apr 197610 Jul 1979National Research Development CorporationTransponders
US4243993 *13 Nov 19796 Jan 1981The Boeing CompanyBroadband center-fed spiral antenna
US4308530 *10 May 197829 Dec 1981N.V. Nederlandsche Apparatenfabriek NedapDetection system forming wide gates with superior spatial selectivity
US4319248 *14 Jan 19809 Mar 1982American Electronic Laboratories, Inc.Integrated spiral antenna-detector device
US4364043 *8 Sep 198114 Dec 1982The University Of AdelaideEfficient object identification system
US4369557 *6 Aug 198025 Jan 1983Jan VandebultProcess for fabricating resonant tag circuit constructions
US4387379 *14 Oct 19807 Jun 1983Raytheon CompanyRadio frequency antenna
US4471345 *5 Mar 198211 Sep 1984Sensormatic Electronics CorporationRandomized tag to portal communication system
US4498076 *10 May 19825 Feb 1985Lichtblau G JResonant tag and deactivator for use in an electronic security system
US4525713 *1 Mar 198325 Jun 1985Lockheed Electronics Co., Inc.Electronic tag identification system
US4598276 *6 Nov 19841 Jul 1986Minnesota Mining And Manufacturing CompanyDistributed capacitance LC resonant circuit
US4636950 *28 Aug 198513 Jan 1987Caswell Robert LInventory management system using transponders associated with specific products
US4646090 *12 Aug 198324 Feb 1987Rca CorporationCodeable identifying tag and method of identification thereof
US4658264 *9 Nov 198414 Apr 1987Minnesota Mining And Manufacturing CompanyFolded RF marker for electronic article surveillance systems
US4673392 *2 Oct 198516 Jun 1987Keime Bernard MPortable self-contained injector for perfusions, particularly in the case of road accident victims
EP0142380A2 *15 Nov 198422 May 1985Minnesota Mining And Manufacturing CompanyElectronic article surveillance system using marker containing a distributed capacitance lc resonant circuit
EP0149240A2 *27 Dec 198424 Jul 1985Polyonics CorporationResonant tag circuits useful in electronic security systems
GB1406500A * Title not available
GB2105952A * Title not available
GB2133950A * Title not available
WO1985004975A1 *23 Apr 19847 Nov 1985Little Inc AResonant tag and deactivator for use in an electronic security system
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5099226 *18 Jan 199124 Mar 1992Interamerican Industrial CompanyIntelligent security system
US5124699 *2 Jul 199023 Jun 1992N.V. Netherlandsche Apparatenfabriek NedapElectromagnetic identification system for identifying a plurality of coded responders simultaneously present in an interrogation field
US5158310 *11 Jul 199027 Oct 1992Tannehill John MDisplay system for shopping cart
US5221831 *29 Nov 199122 Jun 1993Indala CorporationFlap-type portal reader
US5426423 *14 Jun 199020 Jun 1995Raimbault; PierreProcess and device for registering and checking items
US5450070 *4 Apr 199412 Sep 1995Massar; SheppardElectronic missing file locator system
US5461925 *28 Mar 199431 Oct 1995Redken Laboratories, Inc.Assessment of damage in keratin fibers
US5519381 *18 Nov 199321 May 1996British Technology Group LimitedDetection of multiple articles
US5528221 *26 May 199218 Jun 1996Commissariat A L'energie AtomiqueAutomatic identification system for objects or persons by remote interrogation
US5530702 *31 May 199425 Jun 1996Ludwig KippSystem for storage and communication of information
US5565858 *14 Sep 199415 Oct 1996Northrop Grumman CorporationElectronic inventory system for stacked containers
US5574665 *29 Apr 199412 Nov 1996International Business Machines CorporationReceiver apparatus and method for frequency tagging
US5625341 *31 Aug 199529 Apr 1997Sensormatic Electronics CorporationMulti-bit EAS marker powered by interrogation signal in the eight MHz band
US5648765 *8 Mar 199515 Jul 1997Cresap; Michael S.Tag tansponder system and method to identify items for purposes such as locating, identifying, counting, inventorying, or the like
US5661470 *4 Mar 199426 Aug 1997Karr; Gerald S.Object recognition system
US5689238 *8 Mar 199618 Nov 1997Lucent Technologies, Inc.Object locator system and methods therefor
US5721531 *28 Jun 199524 Feb 1998The Whitaker CorporationMonitoring arrangement for electronic file folder locator system
US5726630 *29 Dec 199510 Mar 1998British Technology Group LimitedDetection of multiple articles
US5739765 *18 Jul 199614 Apr 1998Steelcase Inc.File folders for use in an electronic file locating and tracking system
US5742238 *1 Sep 199521 Apr 1998Emtrak, Inc.System for communication between a central controller and items in a factory using infrared light
US5751221 *27 Jan 199512 May 1998Steelcase Inc.Electronic system, components and method for tracking files
US5774022 *29 Aug 199630 Jun 1998Micron Communications, Inc.Digital clock recovery loop
US5787174 *2 Nov 199528 Jul 1998Micron Technology, Inc.Remote identification of integrated circuit
US5883582 *7 Feb 199716 Mar 1999Checkpoint Systems, Inc.Anticollision protocol for reading multiple RFID tags
US5929780 *4 Dec 199727 Jul 1999Pagnol; FredericMethod of monitoring and programming a plurality of transponders simultaneously, and apparatus for implementing the method
US5936527 *10 Feb 199810 Aug 1999E-Tag Systems, Inc.Method and apparatus for locating and tracking documents and other objects
US5963134 *24 Jul 19975 Oct 1999Checkpoint Systems, Inc.Inventory system using articles with RFID tags
US5970398 *29 Aug 199619 Oct 1999Micron Communications, Inc.Radio frequency antenna with current controlled sensitivity
US5977875 *31 Aug 19982 Nov 1999Magnex CorporationCollective objects management system using R.F. object indentification
US5982237 *9 Jan 19989 Nov 1999Micron Communications, Inc.Digital clock recovery loop
US5995017 *24 Nov 199730 Nov 1999Btg International LimitedElectronic identification system confirming valid code
US6002344 *21 Nov 199714 Dec 1999Bandy; William R.System and method for electronic inventory
US6005482 *17 Sep 199821 Dec 1999Xerox CorporationSurface mounted information collage
US6019865 *21 Jan 19981 Feb 2000Moore U.S.A. Inc.Method of forming labels containing transponders
US6028532 *10 Feb 199422 Feb 2000Fujitsu LimitedAutomatic product conveying system
US6034603 *24 Jan 19977 Mar 2000Axcess, Inc.Radio tag system and method with improved tag interference avoidance
US6058374 *20 Jun 19962 May 2000Northrop Grumman CorporationInventorying method and system for monitoring items using tags
US6084512 *2 Oct 19984 Jul 2000Lucent Technologies, Inc.Method and apparatus for electronic labeling and localizing
US6100765 *16 Sep 19998 Aug 2000Micron Technology, Inc.Digital clock recovery loop
US6122494 *13 Oct 199819 Sep 2000Micron Technology, Inc.Radio frequency antenna with current controlled sensitivity
US6127928 *26 Jul 19993 Oct 2000E-Tag Systems, Inc.Method and apparatus for locating and tracking documents and other objects
US6130602 *29 Aug 199610 Oct 2000Micron Technology, Inc.Radio frequency data communications device
US6138058 *6 Jan 199824 Oct 2000Jenoptik Infab, Inc.Method for electronically tracking containers to avoid misprocessing of contents
US6154137 *8 Jun 199828 Nov 20003M Innovative Properties CompanyIdentification tag with enhanced security
US6157230 *14 Sep 19985 Dec 2000Micron Technology, Inc.Method for realizing an improved radio frequency detector for use in a radio frequency identification device, frequency lock loop, timing oscillator, method of constructing a frequency lock loop and method of operating an integrated circuit
US6177858 *27 Nov 199623 Jan 2001Pierre RaimbaultMethod for remotely interrogating tags, and station and tag implementing said method
US619500627 Aug 199927 Feb 2001Checkpoint Systems Inc.Inventory system using articles with RFID tags
US619833222 Sep 19986 Mar 2001Micron Technology, Inc.Frequency doubler and method of doubling frequency
US619835714 Sep 19986 Mar 2001Micron Technology, Inc.Stage having controlled variable resistance load circuit for use in voltage controlled ring oscillator
US62328705 Aug 199915 May 20013M Innovative Properties CompanyApplications for radio frequency identification systems
US6246326 *5 May 199912 Jun 2001Intermec Ip Corp.Performance optimized smart label printer
US624918514 Sep 199819 Jun 2001Micron Technology, Inc.Method of speeding power-up of an amplifier, and amplifier
US627869814 Sep 199821 Aug 2001Micron Technology, Inc.Radio frequency data communications device
US62852615 Jul 20004 Sep 2001Micron Technology, Inc.Digital clock recovery loop
US629495326 Feb 199925 Sep 2001Axcess, Inc.High sensitivity demodulator for a radio tag and method
US6304182 *24 Dec 199816 Oct 2001Mitsubishi Materials CorporationApparatus for detecting theft by a radio wave
US631444022 Sep 19986 Nov 2001Micron Technology, Inc.Pseudo random number generator
US631697528 Sep 199813 Nov 2001Micron Technology, Inc.Radio frequency data communications device
US6326946 *17 Sep 19984 Dec 2001Xerox CorporationOperator icons for information collages
US6331817 *31 May 200018 Dec 2001Motorola, Inc.Object tracking apparatus and method
US63356865 Aug 19991 Jan 20023M Innovative Properties CompanyApplication for a radio frequency identification system
US633763410 Sep 19988 Jan 2002Micron Technology, Inc.Radio frequency data communications device
US63511909 May 200026 Feb 2002Micron Technology, Inc.Stage having controlled variable resistance load circuit for use in voltage controlled ring oscillator
US6356802 *4 Aug 200012 Mar 2002Paceco Corp.Method and apparatus for locating cargo containers
US638464814 Apr 20007 May 2002Micron Technology, Inc.Radio frequency data communications device
US642426213 Mar 200123 Jul 20023M Innovative Properties CompanyApplications for radio frequency identification systems
US644888613 Mar 200110 Sep 20023M Innovative Properties CompanyApplication for radio frequency identification systems
US645621611 Apr 200124 Sep 2002The National University Of SingaporeMethod and apparatus for generating pulses from analog waveforms
US646613129 Aug 199615 Oct 2002Micron Technology, Inc.Radio frequency data communications device with adjustable receiver sensitivity and method
US646663428 Sep 199815 Oct 2002Micron Technology, Inc.Radio frequency data communications device
US646962711 Feb 200022 Oct 2002Marconi Communications Inc.Mounting clip having a wireless communication device
US647674413 Apr 20015 Nov 2002The National University Of SingaporeMethod and apparatus for generating pulses from analog waveforms
US648678019 Jul 200026 Nov 20023M Innovative Properties CompanyApplications for radio frequency identification systems
US6486819 *13 Mar 200126 Nov 2002The National University Of SingaporeCircuitry with resistive input impedance for generating pulses from analog waveforms
US649219211 Sep 199810 Dec 2002Micron Technology, Inc.Method of making a Schottky diode in an integrated circuit
US649857230 Jul 200124 Dec 2002The National University Of SingaporeMethod and apparatus for delta modulator and sigma delta modulator
US649857819 Apr 200124 Dec 2002The National University Of SingaporeMethod and apparatus for generating pulses using dynamic transfer function characteristics
US650983721 Sep 200121 Jan 2003Micron Technology, Inc.Radio frequency data communications device with adjustable receiver sensitivity and method
US657048722 Apr 199927 May 2003Axcess Inc.Distributed tag reader system and method
US65744544 Apr 20003 Jun 2003Micron Technology, Inc.Radio frequency antenna with current controlled sensitivity
US658035711 Feb 200017 Jun 2003Marconi Communications Inc.Handle tag for identification of a container
US660041812 Dec 200029 Jul 20033M Innovative Properties CompanyObject tracking and management system and method using radio-frequency identification tags
US660042019 Jul 200129 Jul 20033M Innovative Properties CompanyApplication for a radio frequency identification system
US660042810 Sep 199829 Jul 2003Micron Technology, Inc.Radio frequency data communications device
US66112232 Oct 200126 Aug 2003National University Of SingaporeMethod and apparatus for ultra wide-band communication system using multiple detectors
US66308975 Aug 20027 Oct 2003Cellonics Incorporated Pte LtdMethod and apparatus for signal detection in ultra wide-band communications
US663320325 Apr 200014 Oct 2003The National University Of SingaporeMethod and apparatus for a gated oscillator in digital circuits
US664655414 Aug 200011 Nov 20033M Innovative Properties CompanyIdentification tag with enhanced security
US66502283 Mar 199918 Nov 2003Commissariat A L'energie AtomiqueMethod an system for reading a dynamic set of tags bearing distinct ID codes
US665026823 May 200218 Nov 2003The National University Of SingaporeMethod and apparatus for a pulse decoding communication system using multiple receivers
US666129821 May 20029 Dec 2003The National University Of SingaporeMethod and apparatus for a digital clock multiplication circuit
US666908912 Nov 200130 Dec 20033M Innovative Properties CoRadio frequency identification systems for asset tracking
US669353929 Nov 200017 Feb 2004Checkpoint Systems, Inc.Inventory system using articles with RFID tags
US669687922 Nov 200024 Feb 2004Micron Technology, Inc.Radio frequency data communications device
US672086511 Feb 200013 Apr 2004Marconi Intellectual Property (Us)Resilient member with wireless communication device
US672128911 Feb 200013 Apr 2004Micron Technology, Inc.Radio frequency data communications device
US67242696 Aug 200220 Apr 2004Cellonics Incorporated Pte., Ltd.PSK transmitter and correlator receiver for UWB communications system
US672780316 Mar 200127 Apr 2004E-Tag Systems, Inc.Method and apparatus for efficiently querying and identifying multiple items on a communication channel
US67351832 May 200011 May 2004Micron Technology, Inc.Radio frequency data communications device
US676841920 May 200227 Jul 20043M Innovative Properties CompanyApplications for radio frequency identification systems
US677161323 Sep 19983 Aug 2004Micron Technology, Inc.Radio frequency data communications device
US67746853 Apr 200010 Aug 2004Micron Technology, Inc.Radio frequency data communications device
US677476621 Jul 200010 Aug 2004E-Tag Systems, Inc.Method for efficiently querying and identifying multiple items on a communication channel
US677478223 Sep 200210 Aug 2004Battelle Memorial InstituteRadio frequency personnel alerting security system and method
US677808811 Feb 200017 Aug 2004Marconi Intellectual Property (Us) Inc.Deployable identification device
US67815089 Dec 200224 Aug 2004Micron Technology IncRadio frequency data communications device with adjustable receiver sensitivity and method
US678481312 Feb 200231 Aug 2004Matrics, Inc.Method, system, and apparatus for remote data calibration of a RFID tag population
US681607521 Feb 20019 Nov 20043M Innovative Properties CompanyEvidence and property tracking for law enforcement
US682576621 Dec 200130 Nov 2004Genei Industries, Inc.Industrial data capture system including a choke point portal and tracking software for radio frequency identification of cargo
US682577311 Sep 199830 Nov 2004Micron Technology, Inc.Radio frequency data communications device
US683646814 Aug 200028 Dec 2004Micron Technology, Inc.Radio frequency data communications device
US683647226 Apr 200228 Dec 2004Micron Technology, Inc.Radio frequency data communications device
US68421211 Aug 200011 Jan 2005Micron Technology, Inc.RF identification system for determining whether object has reached destination
US684791224 Apr 200325 Jan 2005Marconi Intellectual Property (Us) Inc.RFID temperature device and method
US68604223 Sep 20021 Mar 2005Ricoh Company, Ltd.Method and apparatus for tracking documents in a workflow
US690709013 Mar 200114 Jun 2005The National University Of SingaporeMethod and apparatus to recover data from pulses
US69106349 Nov 200028 Jun 2005Hitachi Maxell, Ltd.Information input/ output unit
US69276925 Sep 20029 Aug 2005American Greetings CorporationRF inventory system
US694112411 Feb 20006 Sep 2005Micron Technology, Inc.Method of speeding power-up of an amplifier, and amplifier
US694751330 Mar 200120 Sep 2005Micron Technology, Inc.Radio frequency data communications device
US694771426 Aug 200320 Sep 2005Mattel, Inc.Piezo-powered amusement device identification system
US694777721 Oct 200220 Sep 2005Ward-Kraft, Inc.Compact electronic communication device with self-mounting feature and method of removably coupling such a device to a surface
US695650926 Aug 200418 Oct 2005Symbol Technologies, Inc.Method, system, and apparatus for remote data calibration of a RFID tag population
US69675638 Apr 200222 Nov 2005Ronald BormasterInventory control system
US696756423 Apr 200422 Nov 2005E-Tag Systems, Inc.Method and apparatus for efficiently querying and identifying multiple items on a communication channel
US6968994 *6 Jul 200429 Nov 2005Nortel Networks LtdRF-ID for cable management and port identification
US697268220 Dec 20026 Dec 2005Georgia Tech Research CorporationMonitoring and tracking of assets by utilizing wireless communications
US698975012 Feb 200224 Jan 2006Symbol Technologies, Inc.Radio frequency identification architecture
US700598520 Jul 199928 Feb 2006Axcess, Inc.Radio frequency identification system and method
US70094961 Apr 20037 Mar 2006Symbol Technologies, Inc.Method and system for optimizing an interrogation of a tag population
US7013026 *9 Apr 200214 Mar 2006Paceco Corp.Method and apparatus of automated optical container code recognition with positional identification for a transfer container crane
US701411229 Apr 200321 Mar 2006Hewlett-Packard Development Company, L.P.Electronic identification label and interrogator for use therewith
US70177994 Dec 200128 Mar 2006The Gates CorporationSpindle sleeve with transponder
US70358181 Jun 199925 Apr 2006Symbol Technologies, Inc.System and method for electronic inventory
US70443735 Aug 199916 May 20063M Innovative Properties CompanyRadio frequency identification systems applications
US705436011 Mar 200230 May 2006Cellonics Incorporated Pte, Ltd.Method and apparatus for generating pulse width modulated waveforms
US705751112 Feb 20026 Jun 2006Symbol Technologies, Inc.Method, system, and apparatus for communicating with a RFID tag population
US707543612 Feb 200211 Jul 2006Symbol Technologies, Inc.Method, system, and apparatus for binary traversal of a tag population
US707904324 Jul 200318 Jul 2006Micron Technology, Inc.Radio frequency data communications device
US707904424 Dec 199718 Jul 2006Steelcase Development CorporationElectronic system, components and method for tracking files
US71025236 Apr 20055 Sep 2006Symbol Technologies, Inc.Radio frequency identification tag antenna configurations
US71130941 Dec 200526 Sep 20063M Innovative Properties CompanyApplications for radio frequency identification systems
US712315120 Apr 200417 Oct 20063M Innovative Properties CompanyApplications for radio frequency identification systems
US71298403 Sep 200231 Oct 2006Ricoh Company, Ltd.Document security system
US71454829 Sep 20055 Dec 2006Symbol Technologies, Inc.Method, system, and apparatus for remote data calibration of a RFID tag population
US717086712 Apr 200430 Jan 2007Micron Technology, Inc.Radio frequency data communications device
US717351821 Nov 20056 Feb 2007E-Tag Systems, Inc.Method and apparatus for efficiently querying and identifying multiple items on a communication channel
US719517327 Oct 200327 Mar 2007Symbol Technologies, Inc.Optimization of a binary tree traversal with secure communications
US719971610 Nov 20053 Apr 2007Symbol Technologies, Inc.Method, system, and apparatus for communicating with a RFID tag population
US721212514 Nov 20051 May 2007Symbol Technologies, Inc.Radio frequency identification architecture
US721680523 Jul 200315 May 2007Massachusetts Institute Of TechnologyMethods and apparatus for counting and positioning using resonant tags
US722427324 Apr 200329 May 2007Forster Ian JDevice and method for identifying a container
US725827616 Oct 200121 Aug 2007Promega CorporationRadio frequency identification method and system of distributing products
US72702685 Apr 200618 Sep 20073M Innovative Properties CompanyRadio frequency identification systems applications
US72717279 Nov 200518 Sep 2007Axcess International, Inc.Dual frequency radio tag for a radio frequency identification system
US72830357 Mar 200616 Oct 2007Micron Technology, Inc.Radio frequency data communications device with selectively removable antenna portion and method
US728615822 Dec 199923 Oct 2007Axcess International Inc.Method and system for providing integrated remote monitoring services
US72890159 Aug 200430 Oct 2007Etag Systems, Inc.Method for efficiently querying and identifying multiple items on a communication channel
US72937059 Mar 200413 Nov 2007Promega CorporationRadio frequency identification method and system of distributing products
US729512010 Dec 200413 Nov 20073M Innovative Properties CompanyDevice for verifying a location of a radio-frequency identification (RFID) tag on an item
US73014707 Aug 200227 Nov 2007Steelcase Development CorporationElectronic system, components and method for tracking files
US7308114 *13 Mar 200611 Dec 2007Paceco Corp.Method and apparatus of automated optical container code recognition with positional identification for a transfer container crane
US73213081 Sep 200522 Jan 2008Display Technologies, Inc.Anti-theft holder
US734557528 Oct 200318 Mar 2008Micron Technology, Inc.Radio frequency data communications device with adjustable receiver sensitivity and method
US735730023 Nov 200415 Apr 2008Ricoh Company, Ltd.Method and apparatus for tracking documents in a workflow
US738547729 Nov 200510 Jun 2008Keystone Technology Solutions, LlcRadio frequency data communications device
US74249743 Sep 200216 Sep 2008Ricoh Company, Ltd.Techniques that facilitate tracking of physical locations of paper documents
US747120524 Aug 200630 Dec 20083M Innovative Properties CompanyApplications for radio frequency identification systems
US749738410 Nov 20053 Mar 2009Symbol Technologies, Inc.Methods and systems for the negotiation of a population of RFID tags with improved security
US750495030 Nov 200517 Mar 2009Zih Corp.System and method for continuous RFID encoding
US75062503 Sep 200217 Mar 2009Ricoh Company, Ltd.Techniques for determining electronic document information for paper documents
US751160120 May 200231 Mar 20093M Innovative Properties CompanyRadio frequency identification in document management
US754525628 Nov 20069 Jun 2009Keystone Technology Solutions, LlcSystem and method for identifying a radio frequency identification (RFID) device
US7565307 *21 Dec 200021 Jul 2009Tc License Ltd.Automatic payment method using RF ID tags
US757113917 Feb 20004 Aug 2009Giordano Joseph ASystem and method for processing financial transactions
US758319211 Dec 20061 Sep 2009Keystone Technology Solutions, LlcRadio frequency identification device and method
US75881857 Jun 200115 Sep 20093M Innovative Properties CompanyRFID data collection and use
US759142112 Oct 200522 Sep 2009Promega CorporationRadio frequency identification method and system of distributing products
US76195298 May 200317 Nov 20093M Innovative Properties CompanyApplication for a radio frequency identification system
US76298869 Nov 20058 Dec 2009Axcess International, Inc.Method and system for networking radio tags in a radio frequency identification system
US76525553 Sep 200226 Jan 2010Ricoh Company, Ltd.Container for storing objects
US765398216 Nov 20072 Feb 2010Xerox CorporationIndividually unique hybrid printed antennae for chipless RFID applications
US76615911 Oct 200416 Feb 2010Promega CorporationRF point of sale and delivery method and system using communication with remote computer and having features to read a large number of RF tags
US771027516 Mar 20074 May 2010Promega CorporationRFID reader enclosure and man-o-war RFID reader system
US772873223 Dec 20081 Jun 20103M Innovative Properties CompanyApplications for radio frequency identification systems
US773573224 Jun 200415 Jun 2010Promega CorporationRadio frequency identification method and system of distributing products
US773782329 Oct 200715 Jun 2010E-Tag Systems, Inc.Method for efficiently querying and identifying multiple items on a communication channel
US774623030 Aug 200729 Jun 2010Round Rock Research, LlcRadio frequency identification device and method
US776854612 May 20003 Aug 2010Axcess International, Inc.Integrated security system and method
US77846895 May 200631 Aug 2010Promega CorporationRadio frequency identification method and system of distributing products
US779147913 Nov 20067 Sep 2010Promega CorporationRFID point of sale and delivery method and system
US780050311 May 200721 Sep 2010Axcess International Inc.Radio frequency identification (RFID) tag antenna design
US780836728 Aug 20025 Oct 2010Round Rock Research, LlcRFID material tracking method and apparatus
US781272827 Aug 200712 Oct 2010Round Rock Research, LlcMethods and apparatuses for radio frequency identification (RFID) tags configured to allow antenna trim
US782586726 Apr 20072 Nov 2010Round Rock Research, LlcMethods and systems of changing antenna polarization
US783928529 Aug 200723 Nov 2010Round Rock Resarch, LLCElectronic communication devices, methods of forming electrical communication devices, and communications methods
US784112010 Jan 200730 Nov 2010Wilcox Industries Corp.Hand grip apparatus for firearm
US78445053 Feb 200030 Nov 2010Symbol Technologies, Inc.Automated real-time distributed tag reader network
US785563731 Aug 200621 Dec 2010Forster Ian JDevice and method for identifying a container
US78847241 Dec 20068 Feb 2011Round Rock Research, LlcRadio frequency data communications device with selectively removable antenna portion and method
US78849553 Sep 20028 Feb 2011Ricoh Company, Ltd.Techniques for performing actions based upon physical locations of paper documents
US791267824 Sep 200922 Mar 2011Denny Lawrence AOilfield equipment identification method and apparatus
US79160015 Feb 200729 Mar 2011Etag Systems, Inc.Methods for interrogating objects to be identified over a communications medium
US792884314 Nov 200519 Apr 2011Symbol Technologies, Inc.Method, system, and apparatus for communications in a RFID system
US793286718 Oct 201026 Apr 2011Round Rock Research, LlcMethods and systems of changing antenna polarization
US793626831 Aug 20073 May 2011Round Rock Research, LlcSelectively coupling to feed points of an antenna system
US79423218 Jun 200417 May 2011Promega CorporationRadio frequency identification method and system of disturbing products
US794838211 Sep 200624 May 2011Round Rock Research, LlcElectronic communication devices, methods of forming electrical communication devices, and communications methods
US7961911 *11 Dec 200714 Jun 2011Paceco Corp.Method and apparatus of automated optical container code recognition with positional identification for a transfer container crane
US796518916 Apr 200721 Jun 2011Symbol Technologies, Inc.Radio frequency identification architecture
US796719924 Jul 200928 Jun 2011Promega CorporationRadio frequency identification method and system of distributing products
US800690215 Aug 200730 Aug 20113M Innovative Properties CompanyRadio frequency identification systems applications
US801834024 Oct 200613 Sep 2011Round Rock Research, LlcSystem and method to track articles at a point of origin and at a point of destination using RFID
US8022809 *2 Nov 200620 Sep 2011RFID Mexico, S.A. DE C.V.Inventory taking system
US802522831 Oct 200727 Sep 2011Promega CorporationRF point of sale and delivery method and system using communication with remote computer and having features to read a large number of RF tags
US803107213 Apr 20104 Oct 2011Promega CorporationRFID reader enclosure and man-o-war RFID reader system
US807843322 Jan 200813 Dec 2011Wolfgang KlippelOptimal estimation of transducer parameters
US811342514 Apr 201114 Feb 2012Promega CorporationRF point of sale and delivery method and system using communication with remote computer and having features to read a large number of RF tags
US81156373 Jun 200814 Feb 2012Micron Technology, Inc.Systems and methods to selectively connect antennas to receive and backscatter radio frequency signals
US8120488 *27 Feb 200921 Feb 2012Rf Controls, LlcRadio frequency environment object monitoring system and methods of use
US812531628 Aug 200228 Feb 2012Round Rock Research, LlcRFID material tracking method and apparatus
US813446729 May 200713 Mar 2012Round Rock Research, LlcAutomated antenna trim for transmitting and receiving semiconductor devices
US82310535 May 201131 Jul 2012Promega CorporationRadio frequency identification method and system of distributing products
US824821314 Jun 201021 Aug 2012Etag Systems, Inc.Deterministic method for efficiently querying and identifying multiple items on a communication channel
US82589617 Sep 20114 Sep 2012Promega CorporationRFID reader enclosure and man-o-war RFID reader system
US8269605 *31 Aug 200718 Sep 2012Round Rock Research, LlcRFID material tracking method and apparatus
US832501913 Sep 20104 Dec 2012Ricoh Company, Ltd.Motion tracking techniques for RFID tags
US8378789 *31 Aug 200719 Feb 2013Round Rock Research, LlcRFID material tracking method and apparatus
US83788261 Oct 201019 Feb 2013Checkpoint Systems, Inc.Key device for monitoring systems
US840550921 Nov 201126 Mar 2013Micron Technology, Inc.Systems and methods to selectively connect antennas to receive and backscatter radio frequency signals
US840699328 Aug 200826 Mar 2013Gatekeeper Systems, Inc.Cart braking control during mechanized cart retrieval
US841744529 Aug 20089 Apr 2013Gatekeeper Systems, Inc.System for communicating with and monitoring movement of human-propelled vehicles
US843350729 Aug 200830 Apr 2013Gatekeeper Systems, Inc.Usage monitoring of shopping carts or other human-propelled vehicles
US8441354 *31 May 201114 May 2013Microsoft CorporationRFID-based enterprise intelligence
US845109228 Mar 201128 May 2013Etag Systems, Inc.Method and apparatus for efficiently querying and identifying multiple items on a communication channel
US845286821 Sep 201028 May 2013Checkpoint Systems, Inc.Retail product tracking system, method, and apparatus
US846354020 Mar 200611 Jun 2013Gatekeeper Systems, Inc.Two-way communication system for tracking locations and statuses of wheeled vehicles
US847319228 Aug 200825 Jun 2013Gatekeeper Systems, Inc.Antenna-based zone creation for controlling movement of vehicles
US8478471 *28 Aug 20082 Jul 2013Gatekeeper Systems, Inc.Cart cluster detection and estimation
US849360128 Dec 201023 Jul 2013Ricoh Company Ltd.Techniques for performing actions based upon physical locations of paper documents
US850267325 Mar 20106 Aug 20133M Innovative Properties CompanyApplications for radio frequency identification systems
US85083671 Dec 200913 Aug 2013Checkpoint Systems, Inc.Configurable monitoring device
US855869828 May 201315 Oct 2013Gatekeeper Systems, Inc.Zone-based control of cart usage using RF transmission for brake activation
US85701714 Apr 201329 Oct 2013Gatekeeper Systems, Inc.System for detecting unauthorized store exit events using signals detected by shopping cart wheels units
US857177825 Mar 201329 Oct 2013Gatekeeper Systems, Inc.Cart braking control during mechanized cart retrieval
US860650128 Aug 200810 Dec 2013Gatekeeper Systems, Inc.System for monitoring usage of shopping carts or other human-propelled vehicles
US86247112 Jan 20087 Jan 2014Round Rock Research, LlcRadio frequency identification device operating methods, radio frequency identification device configuration methods, and radio frequency identification devices
US863819425 Jul 200828 Jan 2014Axcess International, Inc.Multiple radio frequency identification (RFID) tag wireless wide area network (WWAN) protocol
US870023031 May 201315 Apr 2014Gatekeeper Systems, Inc.Cart containment system with integrated cart display unit
US8718923 *28 May 20136 May 2014Gatekeeper Systems, Inc.Object cluster detection and estimation
US8723646 *15 Sep 200813 May 2014International Business Machines CorporationAcoustic wave and radio frequency identification device and method
US20100066496 *15 Sep 200818 Mar 2010International Business Machines CorporationAcoustic wave and radio frequency identification device and method
US20110227704 *31 May 201122 Sep 2011Microsoft CorporationRfid-based enterprise intelligence
US20120228240 *8 Mar 201213 Sep 2012T-Ink, LlcIntelligent Display And Fixture System
US20130261943 *28 May 20133 Oct 2013Gatekeeper Systems, Inc.Object cluster detection and estimation
USRE36109 *12 Jul 199523 Feb 1999Kipp; LudwigCheckout system
DE102004055920A1 *19 Nov 200424 May 2006Infineon Technologies AgIdentification system, for identifying objects e.g. in rooms and storage containers, has activation part in room, for providing wireless activation RF signal
DE102007005070A11 Feb 20077 Aug 2008Klippel, Wolfgang, Dr.Linear and non-linear parameters e.g. resistance, estimating arrangement for e.g. failure diagnoses of transducer, has nonlinear estimator with output that receives error free nonlinear parameter, even if estimation error occurs
DE102007005070B4 *1 Feb 200727 May 2010Klippel, Wolfgang, Dr.Anordnung und Verfahren zur optimalen Schätzung der linearen Parameter und der nichtlinearen Parameter eines Modells, das einen Wandler beschreibt
DE102007007717A1 *16 Feb 200721 Aug 2008Deutsche Telekom AgRollcontainer
EP0942385A1 *9 Mar 199915 Sep 1999Commissariat A L'energie AtomiqueProcedure and system for multiple reading of a labelassembly having different identification codes
EP1231562A1 *9 Nov 200014 Aug 2002Hitachi Maxell, Ltd.Information input/output unit
EP1396810A1 *27 Aug 200310 Mar 2004Ricoh Company, Ltd.Container for storing objects
EP2065837A1 *11 Nov 20083 Jun 2009Xerox CorporationIndividually unique hybrid printed antennae for chipless RFID applications
WO1998035327A1 *22 Jan 199813 Aug 1998Checkpoint Systems IncAnticollision protocol for reading multiple rfid tags
WO1998038605A2 *24 Feb 19983 Sep 1998Aharon ShapiraAnti-theft system and method
WO1999005660A1 *15 Jul 19984 Feb 1999Checkpoint Systems IncInventory system using articles with rfid tags
WO2000055797A1 *29 Feb 200021 Sep 2000Ang Chip HongAn educational tool, entertainment system or search tool
WO2000077704A2 *9 Jun 200021 Dec 2000Creative Golf Designs IncInventory control system
WO2013120702A131 Jan 201322 Aug 2013Ebs Ink-Jet Systeme GmbhInkjet printer for labeling goods
Classifications
U.S. Classification340/10.32, 340/572.5, 340/5.92, 340/572.1
International ClassificationG06K19/067, G06Q10/00, G01S13/75, G06K7/10
Cooperative ClassificationG06K7/10009, G06K19/0672, G06Q10/087, G01S13/753
European ClassificationG06Q10/087, G01S13/75C2, G06K7/10A, G06K19/067Q
Legal Events
DateCodeEventDescription
16 Nov 1993FPExpired due to failure to pay maintenance fee
Effective date: 19930829
29 Aug 1993LAPSLapse for failure to pay maintenance fees
31 Mar 1993REMIMaintenance fee reminder mailed
29 Jun 1992ASAssignment
Owner name: REVLON CONSUMER PRODUCTS CORPORATION, NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:REVLON, INC., A DE CORP.;REEL/FRAME:006163/0579
Effective date: 19920624
4 Dec 1990CCCertificate of correction